How to remove libjs-prototype from Debian 9 (Stretch)

Uninstall libjs-prototype

To remove just libjs-prototype package itself from Debian 9 (Stretch) execute on terminal:

sudo apt-get remove libjs-prototype

Uninstall libjs-prototype and it's dependent packages

To remove the libjs-prototype package and any other dependant package which are no longer needed from Debian Stretch.

sudo apt-get remove --auto-remove libjs-prototype

Purging libjs-prototype

If you also want to delete configuration and/or data files of libjs-prototype from Debian Stretch then this will work:

sudo apt-get purge libjs-prototype

To delete configuration and/or data files of libjs-prototype and it's dependencies from Debian Stretch then execute:

sudo apt-get purge --auto-remove libjs-prototype

More information about apt-get remove

Advanced Package Tool, or APT, is a free software user interface that works with core libraries to handle the installation and removal of software on Debian, Ubuntu and other Linux distributions. APT simplifies the process of managing software on Unix-like computer systems by automating the retrieval, configuration and installation of software packages, either from precompiled files or by compiling source code.

apt-get is the command-line tool for handling packages, and may be considered the user's "back-end" to other tools using the APT library.

apt-get remove is identical to install except that packages are removed instead of installed. Note that removing a package leaves its configuration files on the system. If a plus sign is appended to the package name (with no intervening space), the identified package will be installed instead of removed.